Where is the thumb safety on your suggestions?For me, this is a no brainer... Given your price point, IMO there are only a small handful of guns I would trust my life to.
I would say if you can find a P30 (9mm) with LEM trigger, that would be an instant buy. With the price drops HK just made, you are essentially getting a what used to be $950 plus dollar gun for $500ish. Thats an incredible value, and its a gun that meets every single point you have asked for.
Just behind that, I would say go get a G19 either Gen3 or Gen4. Buy them used... there are plenty out and most Glocks are going to last a lifetime. Glocks are the mustang of the firearms world so you can tinker and toy around until your hearts content if you get board with it later on. I would say skip all the other plastic brands outside of Glock and HK. Honestly, with the **** Springfield pulled a few years back... I would never, ever support this company. S&W... eh, just to many moving parts inside with a randomly strange trigger system... Glock just beats it with that point alone.
Other than a G19... a G43 would def be in right behind that choice.
I do like the G42 but, its because of how concealable it is. If you are a bigger dude, just get the 43!
Really, thats the list man...
HK P30 (LEM)
G19 (Gen 3 or Gen 4)
G43
Anything else outside out these guns at the $500 ish dollar mark make very little sense to me. Thats my opinion, its one I have developed over years and years of owning, shooting, and running everything you can imagine right into the ground.
Cheers!